Rubber heel.



G. M. ANDERSON.

Patented Jan. 7, 1919 with the tening nail, to

GEORGE M. ANDERSON, OF WASHINGTON, DISTRICT OF COLUMBIA.

. RUBBER HEEL.

\ Specification of Letters Patent.

Patented Jan. 7, 1919.

Application filed may 17, 1918. Serial No. 235,143.

To all whom it may concern:

Be it known that I, GEORGE M. ANDERSON, a citizen of the United States, resident of Washington, in the District of Columbia, have made a certain new and useful Invention in Rubber Heels; and I declare the following to be a full, clear, and exact description of the same, such as Will enable others skilled in the art to which it appertains to make and use the invention, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

Figure 1 is a bottom plan of the heel.

Fig. 2 is a section on the line 22 before the heel is compressed and with the former in place.

Fig. 3 is a similar view after compression,

former removed and the treadsurface of the plug molded convex. Fig. 4 is a view similar to Fig. 3 with the tread surface of the plug molded flat.

Fig. 5 is a view similarto Fig. 3 with the 4 fastening nail in place.

The invention has relation to rubber heels and. other tread elements for boots and shoes, havingan insertion therein of a friction plug or plugs, having for its object to provide improved means for retaining the plug in the heel.

. The invention consists in the novel construction and combinations of parts, as hereinafter set forth.

coated canvas material, will frequently become detached from its place in or fall out of the heel in use, the cementing or vulcanization connection between the plug and the heel being insecure, and applicant has devised means forming a part of the plug itself, and engaged by the head of the fashold the plug in place.

In the accompanying drawings, illustrating the invention, the numeral 2 designates a hollow or cylindrical friction plug, having a central opening or cavity 3, inserted and cemented within a recess 4 of the lower or tread portion of the heel.

be engaged therewith.

fluid or semi-fluid rubber of the heel will have a tendency to accumulate, as shown in Fig. 2 of the drawings. The upper part of this reduced extension is adapted to form the nail entrance opening or recess 8 in the heel.

' The heel being put under compression in the usual way, and the pressure acting upon all sides thereof, the result is found in practice to be that the upper part of the plug will become compressed inwardly and of less diameter than the lower part of the plug. This inward compression of the upper part of the plug is limited by the reduced extension 6 of the former 5, and will fill the interval 7 displacing the rubber accumulation in said interval, and the upper part of the central cavity 3 of the plug being reduced at 10 to the diameter of said extension and of the shank of the fastening nail to In this operation, the helically wound plug will be formed with bends 11 in its windings or leaves, to provide a shoulder 12, marginal to the perforation or cavity 10 of the upper part of the plug and serving as a back stop for the head 13 of the fastening nail 14.

The upper part of the plug, compressed asstated will be of compact, dense nature, and will form an effectual back stop for the head of the fastening nail, which will at all gimles hold the plug up to its place in the ee i v The lower part of the plug being received in a recess of a mold in the'manufaeture of the heel is protected or guarded against any substantial compression, whereas the upper part of the plug being freely exposed to the compressive forces acting through the semi-fluid rubber will become compressed as stated.

I claim:

1. A rubber tread element for boots and shoes having a recess in its lower portion, and a friction plug disposed in said recess and having a central cavity, said plug having a compressed contracted upper portion overlying said cavity and forming a back-stop for the head of a fastening nail.

2. A rubber tread element for boots and shoes having a recess in its lower portion, and a friction plug disposed in said recess and having a central cavity, said plug of helically wound strip material and having a compressed contractedupper portion overlying said cavity, the normally vertical con- Q i r 1,290,693

volutions of the plug havinginwardly 6X mally vertical convolutions of the plug hav- 10 tending bends at the upper portions thereof. ing inwardly extending bends at the upper 3. A rubber tread element for boots and portions thereof.

shoes having a recess in its lower portion, In testimony whereof I aflix my signature and a friction plug disposed in said recess in presence of two Witnesses.

and having a central cavity, said plug hav- GEORGE M. ANDERSON. ing a compressed contracted upper portion Witnesses:

overlying said cavity, the cavity of the said W. R. BAUM,

upper portion being contracted and the nor- STUART HILDER. 

